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Displaying 2451 - 2475 of 2609

Interim testing artifact (ITA) : a performance evaluation system for coordinate measuring machines (CMMs) : user manual

February 1, 1995
Author(s)
Amy Singer, J Land, Steven D. Phillips, Daniel S. Sawyer, Bruce R. Borchardt, Gregory W. Caskey, D Ward, P Snoots, B Faust
The Interim Testing Artifact (ITA) is designed to quickly test CMMs for performance problems so that they can be repaired before significant numbers of good parts are erroneously rejected (or bad parts accepted) by the CMM. Frequent testing using the ITA

Microform Calibrations in Surface Metrology

February 1, 1995
Author(s)
Jun-Feng Song, F Rudder, Theodore V. Vorburger, A Hartman, Brian R. Scace, J Smith
Microform calibrations include the measurement of complex profile forms and position errors of micrometer scale in combination with the measurement of deviations from a specified profile and surface texture of profile segments. Tolerances on the profile

The Estimation of Measurement Uncertainty of Small Circular Features Measured by CMMs

February 1, 1995
Author(s)
Steven D. Phillips, Bruce R. Borchardt, William T. Estler
This paper examines the measurement uncertainty of small circular features as a function of the sampling strategy, i.e., the number and distribution of measurement points. Specifically, we examine measuring a circular feature using a three-point sampling

A Metrology Approach to Unifying Rockwell C Hardness Scales

January 1, 1995
Author(s)
Jun-Feng Song, J Smith, Theodore V. Vorburger
Current Rockwell C hardness scales (HRC) are unified by performance comparisons. Unless a reliable metrology approach is used for the direct verification of standard hardness machines and diamond indenters, the unified hardness scale may exhibit a

Automated Calibration of Scanning Probe Microscopy by Image Processing

January 1, 1995
Author(s)
J Jorgensen
The continuing drive within high technology industries to push dimensional tolerances to still smaller values motivates the use of surface measuring techniques with better resolution. This requirement can be met by the scanning probe microscopy (SPM)

Calibration Uncertainties for Microform of Rockwell Hardness Indenters

January 1, 1995
Author(s)
F Rudder, Jun-Feng Song
A microform calibration procedure has been developed at NIST to certify geometric conformity of Rockwell C hardness indenters. The interest in microform calibrations is to unify national and international comparisons of hardness tests. Using accepted

Computer Modeling of Heterodyne Interferometer Errors

January 1, 1995
Author(s)
Lowell P. Howard, Jack A. Stone Jr.
A computer model and methodology for modeling optical mixing errors in heterodyne interferometers is presented. The model is based on the Jones calculus and uses a matrix formalism to eliminate simplifications and reduce assumptions in the model. The model

Enhanced Machinability of Silicon Carbide via Microstructural Design

January 1, 1995
Author(s)
Nitin P. Padture, Christopher J. Evans, Hockin D. Xu, Brian R. Lawn
The machinability of a heterogeneous silicon carbide with weak interphase boundaries, elongated grains, and high internal stresses is evaluated relative to a homogeneous control material with a well-bonded, equiaxed, and unstressed grain structure

Error Compensation for CMM Touch Trigger Probes

January 1, 1995
Author(s)
William T. Estler, Steven D. Phillips, Bruce R. Borchardt, Ted Hopp, Christoph J. Witzgall, M Levenson, et al
We present the analysis of a simple mechanical model of a common type of kinematic seat touch trigger probe widely used on modem coordinate measuring machines (CMMs). The model provides a quantitative description of the pre-travel variation or probe lobing

Fabrication of Optics by Diamond Turning

January 1, 1995
Author(s)
Richard L. Rhorer, Christopher J. Evans
The use of special machine tools with single-crystal diamond-cutting tools to produce metal optics is called diamond turning. The manufacture of optical surfaces by diamond turning is relatively new compared to the traditional optical-polishing methods. In

Measurement and Analysis of Forces in Grinding of Silicon Nitride

January 1, 1995
Author(s)
S Jahanmir, T W. Hwang, Eric P. Whitenton, S Job, Christopher J. Evans
Using an instrumented surface grinder, the two components of grinding forces (normal and tangential) were measured for different types of silicon nitride ceramics. The influences of grinding parameters, such as down feed and table speed, and grinding

Measurement of Patterned Film Linewidth for Interconnect Characterization

January 1, 1995
Author(s)
L Linholm, Robert Allen, Michael W. Cresswell, Rathindra Ghoshtagore, S Mayo, H Schafft, John A. Kramar
The results from high-quality electrical and physical measurements on the same cross-bridge resistor test structure with approximately vertical sidewalls have shown differences in linewidth as great as 90 nm for selected conductive films. These differences

Measuring Long Gage Blocks with the NIST Line Scale Interferometer

January 1, 1995
Author(s)
John S. Beers
An improved method for temporarily converting long gage blocks into line scales is described. The new process employs fused silica rather than previously used steel conversion gage blocks. Conversion blocks are pairs of small (13 mm) gage blocks with

Performance Evaluations

January 1, 1995
Author(s)
Steven D. Phillips
The subject of coordinate measuring machine (CMM) evaluation is a broad an multifaceted one. The theme of this chapter is the evaluation of CMM measurement uncertainty which is central to the concept of traceability. This chapter elucidates the sources of
Displaying 2451 - 2475 of 2609